On the seemingly endless road to Nov. 6 and the pivotal midterm elections, the 100-day marker is now in the rear-view mirror.

The dog days of summer will slowly give way to the traditional starting date for the fall campaigns, and the battle lines for control of Congress are clear.

Midterm elections never have been good; they’re usually bad, and often horrific for the party that occupies 1600 Pennsylvania Ave.

{mosads}Since the close of the Civil War, the party that held the White House has lost 36 of 39 congressional midterms, with an average loss of 33 seats. That’s more than enough for the Democrats to wrest control of the House from the Republicans this time.

Calculating the losses of the president’s party since World War II, there’s an average loss of 26 seats, right on the cusp of the 23 net seats Democrats need to win a majority in the House.

History alone suggests a good election night ahead for the Democrats. Beyond that, they’ve been touting other advantages since Donald Trump put his hand on the Bible last January and moved into the White House.

They’ve made a lot of noise about the president’s low approval ratings, magnified each mistaken tweet or verbal miscue, and thrown gasoline on every political spark. All of that has led them to believe that there’s a giant Blue Wave on the horizon, ready to sweep across the land, taking with it many GOP incumbents and giving the Democrats record-setting victories.

But with fewer than 100 days to go, there’s not much evidence of more than a few ripples.

It requires ingesting a lot of blue Kool-Aid to tell folks with a straight face that the Democrats are going to pick up the 60-plus seats in the House that Republicans won in Barack Obama’s last midterm.

It’s equally dubious to argue that the Democrats will win the Senate in 2018. The historical record there is slightly less daunting. There was no direct election of senators until the 20th century. Since the adoption of the 17th Amendment, the president’s party has lost 19 of 26 midterm elections, significantly better than the House fared.

More important is the 2018 electoral map. Democrats are forced to defend 25 seats, 10 of which are states that President Trump carried, and five of which he carried by huge margins. Republicans, meanwhile, have only a few to defend, only one of which Hillary Clinton carried in 2016.

The scenario much more likely to happen than a Blue Wave is a traditional one that’s already playing out. Two or three dozen truly competitive seats will determine who elects the House speaker in January. Those races will be dominated by local flavor and personality as much as the national issues and implications of them.

The “nationalization” of those highly localized races will focus on two things: Democrat attempts to highlight the president’s sometimes polarizing personality and Republican efforts to focus on the booming economy.

Bill Clinton’s 1992 “War Room” displayed the famous admonition, “It’s the economy, stupid.” Americans have voted their self-interest and their wallets since the beginning of the republic. There’s no reason to believe they won’t do so again this year. That’s good news for the Republican Party.

The economy is humming. The recent announcement that GDP growth was over 4 percent for the second quarter is the clearest indicator of where things stand. We’ll likely have growth of 3 percent to 4 percent for the year. That far surpasses anything in the Obama years and is the “rising tide that lifts all boats.”

Unemployment is at a half-century low. Employers are chasing workers, rather than workers searching for jobs. People are taking more money home each week. The stock market is soaring again. Consumer confidence is up. The yield curve is firm. The dollar is sound. Even our trade deficits are under control.

With a lot of miles ahead on the road to Election Day, what could possibly go wrong?

Democrats are hoping for some faux pas bigger than the last one they predicted would be the demise of the Trump administration and Republican Congress.

Republicans are praying that a tariff war won’t put huge bumps in a relatively smooth road.

The economic resurgence we’re experiencing is driven by two things: deregulation and tax cuts. It’s threatened by one thing: blanket tariffs.

Regulation is a tax. Unnecessary and over burdensome regulation stifles growth and takes money out of the economy.

High corporate taxes kill our competitiveness. High individual marginal rates stifle incentive and are counterproductive. Reducing high corporate taxes and individual marginal rates stimulates the economic growth that benefits everybody.

Tariffs are a tax, too, and end up hurting American consumers. Tariffs threaten to curtail our economic boom. Politically, they threaten to hurt individual citizens in the heartland of America — Trump territory. Every time an additional tariff has been announced, the market has responded as expected, putting a dent in the 401(k)s of the Trump constituency.

Larry Kudlow, an economic genius by any definition and the head of President Trump’s National Economic Council, has said pointedly, “I’m opposed to blanket tariffs. In general, I regard tariffs as a very blunt and difficult instrument.”

Kudlow and budget director Mick Mulvaney have argued for policies that will continue the economic boom, not thwart it with restricted tariffs. If they prevail, it’s a big plus for the GOP’s prospects in November.

There’s little doubt that there will be some surprises, in October and at other times, before we get to November.

If Republicans can keep the economy thriving, avoid self-inflicted wounds and stay clear of additional tariff disputes, the Blue Wave may turn out to be little more than a trickle.

Charlie Gerow, first vice chairman of the American Conservative Union, has held national leadership positions in several Republican presidential campaigns. He began his career on the campaign staff of Ronald Reagan. A nationally recognized expert in strategic communications, he is CEO of Quantum Communications, a Pennsylvania-based media relations and issue advocacy firm.